Nano driven Moisture sensors

After watching Bill's video on using the 16,2 Display with I2C board I saw another video for a circuit to indicate if a plant needs to be watered or not (future plans to include a watering circuit). Build it first using and Uno and it worked fine. I then tried it on a breadboard with the Nano and it worked fine. I used an expansion board with screws to connect to the Nano and noticed that with only one 5volt output all three items (2 Capacitive Soil moisture sensors and 1 16,2 Display) have to be tied in together. On the breadboard, I didn't see a problem but now I do. The second Moisture sensor seems to be getting a phantom reading when it's just sitting in the air or even not connected. I run the serial display and you see the numbers change. I have ordered another expansion board for the Nano but it makes it look like the UNO in size.

So Can I run 3 items to the 5volt output and the grounds to the two grounds on the Nano? Do I need to add anything to eliminate the false input?

My other plan is to possibly power it using a 9-volt battery as I have just found adapters that will USB jack.

If I upgrade to a self-watering application I'll be using an Uno or mega for that. I just haven't figured out why switching from the breadboard to the expansion board doesn't work. I have checked my solder connections to all the parts on the expansion board. Nothing found yet.

Any thoughts?

Thanks

Tim